FQT4N20L is a N-Channel enhancement mode power field effect transistor produced by Fairchild Semiconductor Corporation. This transistor uses Fairchild's proprietary planar stripe DMOS technology, which is specially tailored to minimize on-state resistance, provide superior switching performance, and withstand high energy pulses in the avalanche and commutation mode. These devices are well suited for high efficiency switching DC/DC converters, switch mode power supply, DC-AC converters for uninterrupted power supply, motor control.